<div id="sidebar">
      <h1>Sub Menu</h1>
      <div class="submenu"> 
      <a href="http://localhost:8080/FlyGreenwichAirline/">Home</a> 
      <a href="http://localhost:8080/FlyGreenwichAirline/intro.jsp">Introduction</a> 
      <a href="http://localhost:8080/FlyGreenwichAirline/promotion.jsp">Promotion</a> 
      </div>
      
</div>